In a happy manner

Fortuitously or by chance

खुशी से

English Usage: She danced happily at the party.

Hindi Usage: उसने पार्टी में खुशी से नृत्य किया।

Contentedly or with satisfaction

संतोषपूर्वक

English Usage: They lived happily ever after.

Hindi Usage: वे संतोषपूर्वक जीवन जीते रहे।